diyAudio - Another Lepai TA2020 Boombox

I am going on vacation at the end of next week and decided to build boombox I can take as carry on.

I used 4 Radio Shack 40-1354 drivers and 4 cheapo Audax tweeters. The pairs are wired in phase and the tweeters are crossed with a 4uf cap. The box has a basic speaker pocket made with 3/4 plywood and the fronts are skinned with a material I found at the surplus store. Don't know the name but it is pretty easy to work with. It is a 1/4 inch panel with aluminum skin with a plastic triangular comb to give it rigidity and strength. It is light and strong and cuts great in the table saw.

I decided to use a Lepai amp because it is what I had. Had I not had them I would have used something else. The Lepai's are cheaply made and very finicky. I burned one unit. I had to isolate the audio Input ground and the PS ground.

As far as the speaker tuning, I think I ended up with an aperiodic enclosure. Initially drilled a 1.5 inch hole to put a port. I tried different port sizes and looked at the impedance measurements for each. The impedance curve was the flattest with the 1.5 hole plugged with a piece of foam.

The battery is a 12V 7ah SLA battery. I used a DPDT to select between Battery operation and PS operation. In the PS operation the DPDT switch is wired so that the charger can be connected. The battery was connected with a 6amp diode in series so as to have the diode drop when the battery is fully charged. This way I do not have to modify the Lepai to accept the higher voltage.

I used the Lepai case itself as a large nut to hold the amp to the boombox, I used #2 screws.

Sounds quite nice and pretty loud. Need to find out if TSA will allow the SLA battery thru security.